MMC/SD in SPI mode

[Damyus]

I have a question regarding addressing the data stored on a MMC. Is there anyway to know exactly where the data is stored? Is there some way to recover the address where my MP3 file starts?

[Ron Marcus]

I have a question regarding addressing the data stored on a MMC. Is there anyway to know exactly where the data is stored? Is there some way to recover the address where my MP3 file starts?

I would highly suggest checking out the GHI website for ALFAT SD. The file chip makes working with SD and MMC cards a breeze, and you can even buy a board with the chip and SD card connector on board. After working with MMC and SD card systems and trying to get them to work with the changing Windows platforms, this chip is worth every penny.

Ron

[Damyus]

Thanks for the suggestion Ron... but the ALFAT looks a little outta my price range

Let me rephrase the question: When you drag and drop files in windows onto an MMC card (using a standard MMC card reader), is there any way to figure out the starting address of these files or the specific address locations of the files? I am involved in an MP3 player project and am trying to use an MMC to store the MP3 files, and eventually use a PIC to transfer the data through an MP3 decoder chip.

[Ron Marcus]

There are some pretty neat data readers out there, where you can look at the files in their raw state, exactly as they are written to the storage media. I would format a card and put a simple .txt file on it. After which use one of these programs to open it up and examine the structure. The reason to start with a .txt file, is it is one of the simplest structures, and should be the easiest to orient yourself to the inner workings of the storage device. Check www.compsys1.com. Last I checked there was a file reader on that sight.

[Ron Marcus]

I couldn't find it on Compsys1 website...But here are two hex editors that will do the same thing for free, or if you like it, very inexpensive.
www.hhdsoftware.com
www.sb-software.com/hexeditor/

Both should disect the file of interest, with little bloodshed, and no unpleasant formaldehyde smell!

[Damyus]

I couldn't find it on Compsys1 website...But here are two hex editors that will do the same thing for free, or if you like it, very inexpensive.
www.hhdsoftware.com
www.sb-software.com/hexeditor/

Both should disect the file of interest, with little bloodshed, and no unpleasant formaldehyde smell!

wow man thanks a lot that should help a ton